The present application is related to U.S. Application Serial Number (to be assigned), filed herewith, by Jeffrey L. Hall, and entitled, xe2x80x9cArticle Of Manufacture Having A Performance Verification Indicator.xe2x80x9d
The invention relates generally to the field of product performance verification. More specifically, the invention concerns an article of manufacture and method having elements for verifying product performance just prior to use.
Consumers use a variety of means to record images including film based still cameras, digital-based still cameras, and video, to name a few. Film based systems rely on silver halide to record the scene as a latent image that is then manipulated, usually through a processing step, to create a film image of higher, visual density. The film image can be viewed directly as in reversal photography, or it can be scanned and printed as in an all-optical system for color negative photography, or it can be scanned and digitized as in a digital system regardless whether it is reversal or color negative photography. The digitized image can be printed, stored, and/or electronically distributed. All of these image-recording systems have sensitivity to the ambient conditions under which the taking device, the prints, or the electronic data itself are stored.
Consumer research has shown that for film based systems, consumers want assurances that the film is not damaged by temperature and/or weather before the film is used. They worry that the conditions of use such as the camera sitting in too hot an environment, might damage the film. Some consumers are aware that such stressful conditions have ruined pictures that they have taken. Others believe that heat or weather damage was responsible for poor pictures taken, for example, during trips to the beach or while on a vacation when the pictures turn out to have lower quality than expected. Consumers want a system that takes the worry out of their picture-taking activity.
Unfortunately, satisfying this consumer desire poses a dilemma. Unprocessed silver halide based products are chemical based systems that degrade over time. The rate of degradation is dependent on temperature, relative humidity, and background radiation. The extent of this degradation is dependent on the time of exposure to these environmental conditions. Additionally, the extent of the degradation can be modified by the aggregate exposure of the film to these degrading ambient conditions. For example, exposure to a radiation source like that used to x-ray airline packages can generate metallic silver centers that themselves act to accelerate natural age degradation of the film. Alternatively, silver halide-based systems thermally shocked by exposure to high temperature such as in the glove box of a car have accelerated degradation processes at these high temperatures than if the system were always stored at 70xc2x0 F.
The silver halide based product manufacturer can use product design and product packaging to help manage this inherent system instability, but not eliminate it. They can control temperature, humidity and storage location to manage background radiation effects in order to slow the rates of these degradation processes to some extent. Additionally, they can control inventory within their distribution channels to increase a product""s turnover per year in order to reduce the age of the product in the supply chain before a consumer purchases the product. However, they make no attempt except for expiration dating at controlling the film inventory of a consumer.
Silver halide based product manufacturers can add expiration dating to the package to encourage the consumer to use the film within a specified period of time. However, silver halide based systems exposed to high temperature conditions associated with storage of, for example, a loaded camera or roll of film in the glove box of an automobile, can degrade considerably faster than predicted by the expiration dating on the box. That is, the expiration dating is a guide to the quality of the film under less stressful storage conditions. Once the product is in the consumers hands, particularly when the product is loaded in a camera for film based systems, such managed control of temperature, relative humidity, and background radiation exposure is generally lacking. In addition, the time the product is used by the consumer varies widely, thus leading to product utilization that is well beyond the optimum performance capability of the product. In addition to providing a means of assurance to the consumer that the product is good, it would be desirable to increase the rate at which product held by the consumer is used so that the product is used nearer its peak performance.
Consumers can purchase film as single rolls or in multipack blocks of films. The former are often available in retail stores while large multi-pack block sales are often associated with discount warehouses. The trade recognizes that individual consumers have an average rate at which they use film. Therefore, the time between film purchases is longer when film is purchased in a large block. Since the film within such a large block is most frequently from the same time of manufacture, then, until this film is fully consumed, it will be aging while in the hands of the consumer. That is, there is a film age distribution curve 5 in FIG. 1, which occurs in the marketplace because of the purchase and usage patterns of the consumers. The x-axis in this plot is the age of the film and the y-axis is the frequency that a film of age xe2x80x9cXxe2x80x9d months is observed in the trade.
Temperature, relative humidity and background radiation, all factors that can impact the quality of recorded images, are often closely controlled from the time of manufacture through the distribution chain. However, they are not controlled after the consumer purchases the film. Manufacturers attempt to address this issue by providing expiration dating 10 as shown in FIG. 1. This is the date that the manufacturer uses to set an upper limit to the film""s lifetime in the trade. Consumers implicitly assume the film is good until then. However, expiration dating is only a general guide. It does not take into account how the consumer in fact handled the film during this time of storage and usage. In fact, film can be very rapidly degraded if the film is treated to severely high temperatures. Such might occur for a film or a loaded camera left in a closed automobile. Gibbs, et al. report that temperatures within an enclosed automobile can reach 120xc2x0F. within 10 minutes and 140xc2x0F. within 40 minutes when the ambient temperature is 93xc2x0F. (J. La. State Med. Soc., Vol. 147, December 1995, pages 545-546). It is common for consumers to have their film or loaded cameras in the car, thus subjecting the film to thermal events that are not part of the average treatment conditions anticipated by film manufacturers when they expiration date the film.
Given that the film degrades over time, there is an optimum range of age wherein the film is at peak capability, say over the time depicted by 20 in FIG. 1. Film that is older begins losing this peak performance. Film used past the manufacturer""s expiration date may still provide pictorial results, but the resultant images are not as good as those that could have been obtained earlier in the film""s life. This is to be expected. If it were different, then manufacturers would extend the expiration dates to a longer time. Expiration dating is an inefficient method to assure the consumer that the film they have purchased is still good.
Therefore, there persists a need in the art to develop a method that enables consumers of fungible products, such as photographic film, to verify that the film product is still good for quality picture taking based on the consumer""s storage and usage of the film.
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method of verifying the usability of a photosensitive film product just prior to use includes the step of applying at least one environmental sensitive label to the photosensitive film product. The environmental sensitive label has affixed thereto at least one cumulative time temperature indicator and at least one thermal event indicator for independently determining the performance of the product in a predetermined environment.
The present invention has numerous advantages over prior art developments. First, the method of the invention enables the user of photosensitive film product to determine product performance in predetermined environment. Further, the method uses independent indicators of product performance affixed to the product or packaging to assist the user in verifying product performance. Moreover, the method of the invention is relatively simple to employ.